Method of preparing shoe parts for adhesive attachment to other shoe parts



May 22, 1934. WEDGER I 1,959,605

METHOD OF PREPARING SHOE PARTS FOR ADHESIVE ATTACHMENT TO OTHER SHOE PARTS Filed Nov.. 9. 1931 //v VE/V 7Z7/P.

mm H g Patented May 22, 1934 METHOD OF PREPARING SHOE PARTS FOR ADHESIVE ATTACHMENT TO OTHER SHOE PARTS Walter H. Wedger, Belmont, Mass, assignor to United Shoe Machinery Corporation, Paterson, N. 3., a corporation of New Jersey Application November 9, 1931, Serial No. 573,923

9 Claims. (Cl. 12-146) This invention relates to methods of preparing shoe parts for adhesive attachment to other shoe parts and it relates also to improved articles of manufacture such as may be produced by the practice of such methods. In its method aspect the invention is herein exemplified in its application to the preparing of outsoles for attachment by pyroxlin cement to the bottoms of lasted shoes.

In the manufacture of shoes of the type in which the outsole is secured to the shoe principally or wholly by means of cement it is well known that the bond between the cement and the outsole is made more secure if the surface of the 15 outsole is roughened preparatory to the application of the cement.

One object of the present invention is to provide for roughening the surfaces of shoe parts such, for example, as outsoles, in a manner fur- 0 ther to facilitate the attachment of the parts by adhesive and to insure a more secure attachment of the parts than has heretofore been found to be practicable.

To the accomplishment of this object, as herein exemplified, the portion of an outsole which is to be cemented to the bottom of a shoe is prepared for the reception of the cement by roughing the surface of the sole in such a manner as to provide an increased area of surface for the cement to adhere to and also to expose the fibers within the body of the leather without, however, tearing, shredding, or otherwise acting upon the leather in such a manner as to weaken the fibers or loosen them from the under body, and thus to render them unserviceable for retaining the ocment. This roughing operation, asherein illustrated, results in forming in the margin of the sole a series of scratches, grooves or furrows which extend in directions oblique to the sole edge, the furrows being so formed as to expose the fibers of the leather to the action of the cement for a substantial distance below-the surface of the sole without unduly loosening or weakening the fibers, and the furrows being of substantial depth and 4 width and being arranged in closely adjacent but substantially non-intersecting relation thereby producing a ridged and furrowed (or hill-anddale) surface formation which substantially increases the area of surface available for engage- O ment by the cement. Moreover, inasmuch as the furrows are obliquely disposed relatively to the sole edge they tend to prevent squeezed-out of the cement as a result of the sole-attaching pressure and thus insure against defacement of the 55 sole edge and the upper by surplus cement. The

practice of this improved method avoids the formation upon the surface of the sole of a tangled or matted mass of weakened fibers more or less loosened or disconnected from the under body such as would tend to prevent the cement from securely gripping the firm or solid portion of the sole. Moreover, inasmuch as the furrows penetrate rather deeply into the leather where the texture is more dense than at the surface and where the fibers are more firmly compacted together, the cement is enabled to grip those firmly anchored fibers thereby insuring a secure bond between the cement and the sole.

After being roughened the outsole, as exemplified herein and in accordance with a customary practice, is coated with cement and the cement is allowed to dry and is later activated by a suitable solvent prior to the laying of the sole. Preferably pyroxylin cement is employed the character of which is such that the cement will tend to" hug the roughened surface so that the outer surface of the cement coating will be furrowed to correspondsubstantially to the contour of the furrowed surface of the leather. This furrowed characteristic of the outer surface of the cement coating is taken advantage of during the application of the solvent, in accordance with another aspect of the present invention, as herein exemplified, inasmuch as the furrows are utilized as pockets to entrap and hold a quantity of solvent in excess of that required to activate the cement constituting the said coating and this surplus solvent may advantageously be utilized to activate also another coating of cement previously applied to-and left to dry upon the overlasted margin of a shoe upper to which the sole is to be attached. By this'practice a separate application of solvent to cemented overlasted margins of the shoe upper is rendered unnecessary and a substantial saving of time and. labor is effected.

Regarded in another aspect, invention is also to be recognized as residing in an improved article of manufacture which may be produced by the practice of the improved method above disclosed and which, in the illustrated embodiment of the invention, consists of a shoe part illustrated as an outsole having formed in its surface a series of furrows for increasing the area of the surface ,to be engaged by the cement, the furrows extending in directions oblique to the edge of the shoe part and being of substantial depth and width, sufiicient to allow the cement to have direct and immediate access to the fibers of the leather in regions located a substantial distance beneath the surface of the leather, and the furrows being substantially straight and arrangedin close but non-crossing relation to avoid unduly tangling or matting of the exposed fibers.

The above and other features and aspects of the invention will be better understood and appreciated from reading the following description of one exemplification thereof in connection with the accompanying drawing, in which Fig. 1 is a perspective view of apparatus such as may conveniently be employed for roughing the margin of an outsole, illustrating the mode of operation of the apparatus upon a sole;

Fig. 2 is an elevational view of a cement applying device illustrating the manner of applying a coating of cement to the roughened margin of the sole;

Fig. 3 is a perspective view illustrating the manner in which the cement coating upon the sole may be conditioned by the application of a solvent thereto;

Fig. 4 is a perspective view of an outsole as it appears after its margin has been roughened;

Fig. 5 is a sectionalview, on an enlarged scale, taken along the line V-V of Fig. 4;

Fig. 6 is a view similar to Fig. 5, but showing the sole as it appears after the coating of cement has been applied to the roughened margin thereof;

Fig. 7 is a view similar to Fig. 6, but illustrating the appearance of the sole after the solvent has been applied to the cement coating; and

Fig. 8 is an enlarged sectional view illustrating, more or less conventionally, the character of the bond that is formed between the sole and the upper of a shoe.

As illustrated in Fig. 1 of the drawing, an outsole 14 is prepared for the reception of cement by having its marginal portion at the flesh side roughened by the action of a rotary roughing tool 16 while the sole is being fed past the tool.

1 The roughing tool 16 is constructed and arranged "to produce a multitude of substantially nonintersecting scratches or furrows 18 in the surface of the sole margin which extend in directions oblique to the sole edge as indicated in Figs. 1 and 4. To this end, the illustrated tool 16 has a work engaging periphery composed of the extremities of.,a series of resilient metallic bristles and the tool is disposed with its axis inclined with respect to the direction in which the sole is to be fed. As shown, the sole is supported by a lower feed roll 20 arranged to cooperate with the roughing tool 16 to feed the sole in the direction of the arrow 22 in Fig. 1, while the position of the sole relatively to the tool 16 is determined by means of fixed edge gages 24. The above-described means for performing the roughing operation is not claimed herein, the same being the subject-matter of a copending application, Serial No. 594,069, filed February 19, 1932, in the. name of Charles G. Brostrom.

The scratches or furrows 18 formed in the sole by the action of the roughing tool 16 are approximately straight and parallel and preferably, as above described, they are disposed in oblique relation to the sole edge, it having been found that such an arrangement of the furrows tends to prevent the cement, which is later applied to the roughened sole margin, from being squeezed outwardly across the sole edge as a result of the pressure to which the sole is subjected during the sole laying operation. Moreover, the illustrated furrows are of substantial depth and width and they are arranged close together so as to produce a surface comprising a series of alternately disposed furrows and ridges, as best shown in' Figs. 5 to 8, the ridges being of substantially the same width as the furrows and being deep and wide enough to expose the leather fibers in the firm body of the insole to the action of the cement. The furrows 18 being formed by substantially unidirectional movements of the bristles of the roughing tool transversely across the sole margin, there will be no criss-crossing of the furrows such as would inevitably occur if the furrows were to be indefinitely extended lengthwise of the sole margin. Consequently the fibers will not become unduly tangled or matted in such a manner as would tend to prevent the cement from directly engaging and effectively adhering to the fibers in the deeply furrowed portions of the surface. On the contrary, the fibers at the bottoms of the furrows are rendered easily accessible to the cement and, inasmuch as the fibers located below the surface of the sole are more firmly felted or compacted together than those which are nearer to the, surface, the adhesion of the cement to the more firmly felted fibers insures amore secure attachment of the sole to a shoe than if the bond between the cement and the sole were restricted to the looser fibers at the surface of the sole.

After the margin of the sole has been roughened, as above described, a coating of cement is applied to the roughened margin and permitted to dry thereon so that a solidified layer of cement is superimposed upon the roughened surface as indicated at 28 in Fig. 6. The cement may advantageously be applied to the sole margin by means of apparatus such as that shown in Fig. 2 wherein a sole supported by a driven lower feed roll 30 is fed beneath an upper cement applying roll 32, while the position of the sole with respect to the roll 32 is determined by means of an edge gage roll 34. As shown, the cement applying roll 32 is arranged to rotate within the lower portion of a cement tank, a portion of which is indicated at 36, and the periphery of the roll 32 is knurled as shown at 38 to facilitate application of the cement to the surface of the sole. The cement applying apparatus just described is not claimed herein, however, the same having been made the subject-matter of a copending application Serial No. 511,808, filed January 28, 1931, in the name of Arthur S. Johnson.

In accordance with the usual custom a coating of cement is applied also to the overlasted margin of the upper of the shoe to which the sole is to be attached and advantageously the upper margin may be prepared to receive the cement by a roughing operation similar to that already described whereby a ridged and furrowed surface corresponding to that in the sole is formed in the upper margin.

The cement coating 28 upon the sole is softened by application thereto of a suitable solvent prior to the laying of the sole upon the shoe bottom.

The solvent may conveniently be applied manually by means of a brush 40 as indicated in Fig. 3.

Preferably pyroxylin cement is employed having a plasticity and surface tension such that the cement will not flow freely after engaging the sole but will tend to hug or cling to the roughened contour of the sole margin so that after the cement has been allowed to dry its outer surface will be characterized by the presence of furrows and ridges corresponding to those in the roughened surface of the leather. The furrows in the outer surface of the cement layer, which are indicated at 42 in Fig. 6, are utilized as pockets to entrap and hold a surplus amount of solvent (as illustrated at 44 in Fig. 7) so that the solvent, in addition to activating the cement on the outsole, may be utilized also to activate the layer of cement upon the overlasted margin of the shoe upper, thus rendering it unnecessary to perform a separate operation of applying solvent to the cement on the shoe upper margin.

After the solvent has been applied to the cement on the outsole the outsole is laid and held against the lasted shoe bottom under pressure in the manner customary in the making of cement process shoes to effect a union between the meeting surfaces of the two layers of cement. Inasmuch as these layers of cement have already been secured, one to the sole and the other to the upper, a union is now obtained between the sole and the upper. Certain characteristics of the union between the sole and the upper are more or less conventionally illustrated in Fig. 8 wherein it appears that the coating of cement on the sole 14 and the coating of cement on the upper 46 have been united to form, in effect, a unitary cement layer as indicated at 48. As shown, this cement layer 48 is characterized by having a series of ridges 50 at one side filling the furrows 18 in the outsole and a corresponding series of ridges 52 at the opposite side filling the furrows in the shoe upper. The bond thus produced is, of such a character that there is practically no danger of the sole peeling or scaling from the shoe. As will be apparent from an examination of Fig. 8, the ridges or ribs 50 and 52 of cement are securely felted to the firmly welted fibers in the bottom portions of the furrows in the outsole and in the shoe upper, there being no tangled and matted mass of loosened and weakened fibers interposed between the cement and the firm under body of the leather at either side of the cement. Consequently, a secure and lasting attachment of the sole to the shoe is insured.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of roughing shoe soles to prepare them for the reception of adhesive to secure them to shoes which consists in forming in the margin of a sole a ridged and furrowed surface wherein the ridges and furrows extend only in directions oblique to the sole edge.

2. That improvement in methods of preparing soles for adhesive attachment to shoes which consists in forming in a sole a furrowed surface wherein the furrows extend in directions oblique to the sole edge, coating said surface with an adhesive which will not fiow freely after being applied, and allowing the adhesive to solidify thereby producing a layer of solidified cement characterized by having a furrowed outer surface corresponding to the furrowed surface of the sole.

3. That improvement in methods of preparing leather soles for adhesive attachment to shoes which consists in forming in a leather sole a roughened surface comprising a series of distinctly defined approximately straight and parallel furrows extending in directions oblique to the adjacent edge of the sole, the furrows being of substantial depth and width to provide an increased area of surface for engagement by the cement and to facilitate the bonding of the cement to the fiber within the body of the leather, and forming upon said roughened surface a cement coating having in its outer surface a series of furrows corresponding in form, size and location to those in the surface of the sole.

4. That improvement in methods of preparing soles for adhesive attachment to shoes, which consists in forming on a sole a ridged and furrowed surface wherein the furrows extend in directions oblique to the sole edge, coating said surface with a cement which will not flow freely after being applied thereby producing a layer of cement characterized by having a ridged and furrowed outer surface corresponding to that of the sole, and applying to the ridged and furrowed surface of the cement coating a sufiicient amount of solvent to soften the coating and to leave a surplus of free solvent entrapped in the furrows of the coating for use in softening a coating of cement upon a shoe.

5, That improvement in methods of preparing leather soles for the reception of cement to-secure thorn to shoes which consists in moving a series of roughing members in substantially parallel paths across the margin of a sole in directions oblique to the sole edge to form a series of substantiallystraight an I parallel scratches extending obliquely across the sole margin.

6. An article of manufacture comprising a leather shoe part having a surface adapted for adhesive attachment to another shoe part, said surface being characterized by a series of approximately straight and substantially parallel furrows of substantial depth and width extending in directions oblique to the adjacent edge of the part, a layer of cement on said surface provided upon its under side with a series of ridges filling said furrows and hav.ng direct holding engagement with the fiber of the leather at the bottoms of the furrows and having upon its opposite side a series of furrows corresponding to the furrows in the shoe part, and a quantity of cement solvent entrapped in the furrows in the outer surface of said cement layer.

7. An article of manufacture comprising a leather sole having a marg.nal surface prepared for the reception of cement by having formed in said surface aseries of substantially parallel furrows and ridges extending in directions oblique to the adjacent edge of the sole.

8. An article of manufacture comprising a leather sole having a marginal surface prepared for the reception of cement by having formed in said surface a series of substantially parallel furrows and ridges extending in directions oblique to the adjacent edge of the sole, and a layer of cement on said furrowed surface having the outer surface of the cement ridged'and furrowed to correspond to the ridged and furrowed surface of the sole.

9. A shoe sole having a furrowed surface wherein the furrows extend in directions oblique to the sole edge, a layer of cement upon said furrowed surface, said layer having an outer surface furrowed to correspond to the furrowed surface of the shoe part, and a quantity of cement solvent entrapped in the furrows in the outer surface of said cement layer.

WALTER H. WEDGER.

CERTIFICATE OF CORRECTION.

Patent No. 1,959,605. May 22, 1934.

WALTER H. WEDGER.

It is hereby cc. tified that errorappears in the printed specification of the above numbered parent requiring correction 'as follows: Page 3, line 36, for "felted" read welded; and in same line, for "welted" read felted; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of August, A. D. 1934.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

